J/A+A/525/A127ivo://CDS.VizieR/J/A+A/525/A127doi:10.26093/cds/vizier.35250127CDSTasse C.Roettgering H.Best P.N.2012-05-22T14:21:36Z2011-06-10T16:05:57ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.fractive-galactic-nucleix-ray-sourcesvisible-astronomysloan-photometryinfrared-photometryThere is mounting evidence that active galactic nuclei (AGN) selected through optical emission lines or radio luminosities comprise two distinct AGN populations, whose activity is triggered by different processes. In two previous papers, we studied the host galaxies and environment of radio-loud AGN. In this third paper we study the properties of a sample of Type-2 AGN that were selected on the basis of their [2-10]keV X-ray luminosity. We find that the X-ray luminosity function is in good agreement with previous studies and that the fraction of galaxies hosting an X-ray AGN is a strong function of the stellar mass of the host galaxy. The shape of this fraction-mass relation is similar to the fraction of galaxies that are emission-line AGN, while it differs significantly from the relation observed for radio-selected AGN. The AGN in our sample tend to be located in underdense environments where galaxy mergers and interactions are likely to occur. For all host galaxy masses, the Type-2 AGN display a strong infrared excess at short (~3.5um) wavelengths, suggesting the presence of hot dust possibly associated with a hot dusty torus. These results add weight to the belief that the X-ray selection criteria identifies a population of AGN similar to the emission-line selected population but distinct from the radio population at high masses.2011A&A...525A.127Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/525/A127CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/382/279 : XMM-LSS catalogue. Version I. (Pierre+, 2007)J/ApJ/591/640 : XMM-LSS low-frequency radio counterparts (Cohen+, 2003)J/A+A/456/791 : XMM-LSS field at 74 and 325MHz (Tasse+, 2006)J/A+A/471/1105 : XMM-LSS at 240MHz and 610MHz (Tasse+, 2007)J/A+A/474/473 : XMM-LSS survey: AGN classifications (Garcet+, 2007)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/525/A127https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/525/A127http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/525/A127https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/525/A127https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/525/A127http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/525/A127GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/525/A127/tablea1 (Properties of the selected Type-2 X-ray sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/525/A127/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/525/A127/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/525/A127/tablea1?GETtext/xml+votable180.050000true34.8160417-4.49705280.0055555555555555565/4422 6/17683 17686 17692-176942.0616683193919197e-20 6.090060298487514e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/525/A127?format=asciiX-rayOpticalInfrareddefaultJ/A+A/525/A127/tablea1Properties of the selected Type-2 X-ray sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameX-ray source name, XNNNNmeta.id;meta.maincharlogFxs? X-ray source flux in soft 0.5-2keV bandlog(mW.m**-2)phot.flux;em.X-rayfloatnullablelogFxhX-ray source flux in hard 2-10keV bandlog(mW.m**-2)phot.flux;em.X-rayfloatRAOOptical counterpart right ascension (J2000)meta.id.assoc;pos.eq.raDEOOptical counterpart declination (J2000)meta.id.assoc;pos.eq.decl_umagLimit flag on umagmeta.code.errorcharumag? u-band magnitude in AB system (1)magphot.mag;em.opt.Ufloatnullablegmag? g-band magnitude in AB system (1)magphot.mag;em.opt.Bfloatnullablel_rmagLimit flag on rmagmeta.code.errorcharrmagr-band magnitude in AB systemmagphot.mag;em.opt.Rfloatimagi-band magnitude in AB systemmagphot.mag;em.opt.Ifloatl_zmagLimit flag on zmagmeta.code.errorcharzmag? z-band magnitude in AB system (1)magphot.mag;em.opt.IfloatnullablePidEstimated probability that the X-ray source is associated with the corresponding optical candidate%statfloatl_[3.6]Limit flag on [3.6]meta.code.errorchar[3.6]? Spitzer/IRAC 3.6um magnitude (AB) (2)magphot.mag;em.IR.3-4umfloatnullablel_[4.5]Limit flag on [4.5]meta.code.errorchar[4.5]? Spitzer/IRAC 4.5um magnitude (AB) (2)magphot.mag;em.IR.4-8umfloatnullablel_[5.8]Limit flag on [5.8]meta.code.errorchar[5.8]? Spitzer/IRAC 5.8um magnitude (AB) (2)magphot.flux.density;em.IR.4-8umfloatnullablel_[8.0]Limit flag on [8.0]meta.code.errorchar[8.0]? Spitzer/IRAC 8.0um magnitude (AB) (2)magphot.flux.density;em.IR.8-15umfloatnullablezphPhotometric redshift as estimated by ZPEGsrc.redshiftfloatlogMStellar mass as estimated by ZPEG in logarithm base-10 scalelog(solMass)phys.mass;meta.modelledfloatlogSFR? Specific SFR as estimated by ZPEG in logarithm base-10 scale (-{infty} when blank)log(yr**-1)phys.SFRfloatnullablel_lognHLimit flag on lognHmeta.code.errorcharlognHEstimated hydrogen column densitylog(cm**-2)phys.columnDensityfloatlogLXEstimated rest-frame intrinsic X-ray luminosity in the 2-10keV bandlog(1e-07W)phys.luminosity;em.X-rayfloatXLSSX-ray sources from XMM-LSS catalog (Pierre et al. 2007n Cat. J/MNRAS/382/279)meta.ref.urlcharRAJ2000X-ray source right ascension (J2000)pos.eq.ra;meta.mainDEJ2000X-ray source declination (J2000)pos.eq.dec;meta.main